Aqueous chemical mixture to mitigate water associated problems in concrete pavements

ABSTRACT

A water-based mixture of multi compounds was invented for the purposes of treating and providing an ultimate protection for large areas of concrete pavements against moisture and moisture-associated problems. The mixture preferably works from within the concrete as well as at the surface. A water-repelling function prevents water from penetrating the concrete matrix. A hygroscopic and hydrophilic behavior of its crystallization system within a concrete matrix minimizes moisture transmission through capillaries and connected voids. As a result, the mixture promises to provide a permanent treatment for moisture related problems, such as damage caused by repeated freeze and thaw cycles and chloride ion penetration as from deicing salts, as well as a permanent treatment for the so-called alkali-silica reactions.

FIELD OF THE INVENTION

The present invention relates to a water-based mixture of multi-chemicalcompounds, to a method of production thereof, and to a method using thismixture for cost-effective treatment and protection of concretepavements on a large scale against moisture and water-associatedproblems.

More particularly, the present invention, being a complex water-basedmixture of several active chemicals, was developed for the purpose ofminimizing water penetration into concrete pavements from the surface,utilizing a chemical repelling agent, as well as minimizing thetransmission of water and vapor through the concrete matrix (includingfrom below) with a crystallization system, preferably a double actioncrystallization system of hygroscopic and hydrophilic behavior, allpreferably based upon a single treatment, the chemical mix preferablyshipped and stored in a single container and preferably applied byspraying. The invention is primarily intended for the treatment andprotection of concrete bridges, concrete highways and concrete airportrunways and taxiways and the like by a single application that resultsin essentially permanent maintenance-free and worry-free concretepavements when it comes to water problems. As a further benefit, thetreatment should prolong the concrete service life.

BACKGROUND OF THE INVENTION

Concrete structures are considered to be highly porous materials. Theporosity primarily exists in the form of pores that are connectedthrough capillary channels. Concrete voids are also formed as a resultof air entrapped as well as water movements through the settling processand evaporation due to heat generated by the exothermic reaction ofcement hydration. While it is important to maintain to a certain degreevoids within the concrete in order for the so-called process of concretebreathing to take place, the porosity of concrete enhances thepermeability of water in liquid and vapor phases through flow,diffusion, or sorption. This induces well documented water-associatedproblems within the concrete, such as the Alkali-Silica Reaction, freezeand thaw spalling as well as chloride ion penetration Such problemsresult in concrete deterioration which in return reduces the concretestructure's life span, especially if the reinforcement steel starts tocorrode as a result of an oxidation process that is greatly enhanced bywater and chloride ions (FIG. 1).

There are several water-associated problems in concrete. The most severeproblems caused by water take place under wet conditions as a result ofdissolving concrete alkalis, repeated freezing and thawing cycles andchloride ion penetration. Such conditions may result in further problemslike spalling, silicate dusting, stress cracks, laitance andefflorescence, as shown in FIG. 2.

The hydration of cement produces calcium silicate hydrates with anamorphous structure that binds sand and aggregate to form a rigidconcrete structure. The hydration process also produces calciumhydroxide, Ca(OH)₂, as a bi-product, which makes the concrete a highlyalkaline material. In the presence of water, either in the liquid or thevapor stage, the hydroxide material becomes in the solution form with apH value that can exceed 12.5, within the concrete matrix. This solutionis considered chemically aggressive to the cement paste itself and tosome minerals in the aggregate.

Siliceous materials, such as volcanic glass, opal, strained quartz, andcristobalite are particularly susceptible to hydroxide material in thissolution form what results is known as the Alkali-Silica Reaction,commonly referred to as “ASR”. ASR is a heterogeneous chemical reactionthat takes place within concrete between the alkaline pore solution ofthe cement paste and silica containing parts of the aggregate particles.The product of such reaction is silicate gel that is able to combinewith more water and swell. The swelling process results in an internaltensile strength build-up within the discontinuous aggregate pores. Overtime, the internal pressures caused by the swelling process issufficiently strong to cause cracking of the paste matrix which then canresult in a compromised concrete with an open door to an increasing rateof deterioration. See Jakobsen, U. H., Thaulow, N. “Cause ofdeterioration of Canadian concrete railroad ties: Geology of aggregatesource and concrete examination” Proc. 6th Euroseminar on MicroscopyApplied to Building Materials, ICELAND, pp 187-206, 1997. Jensen, V.,Meland, I. and Justnes, H.: “Alkali Aggregate Reaction in Concrete”,Proceedings of 14^(th) Nordic Concrete Research Meeting, Trondheim,Norway, pp. 62-63, August 1990. Geiker, M., Thaulow, N. “The MitigationEffect of Pozzolans on Alkali-Silica Reactions” 4th CANMET/ACIInternational Conference of Fly Ash, Silica Fume, Slag and NaturalPozzolans in Concrete, Istanbul, May 3-8, 1991. Haugen, M. and Jensen,V.: “Petrographic Analyses of Norwegian Slow/Late Expansive AlkaliReactive Aggregate”, Proceedings of 15th Nordic Concrete ResearchMeeting, Gothenburg, Sweden, pp. 17-19, August 1993.

In climates where repeated cycles of freezing and thawing occur,concrete with sufficient moisture is susceptible to damage. Whentemperature drops below the freezing point ice starts to form within thepores of concrete. Since water increases its volume by 9% on freezing,water confined in pores between freezing bodies are therefore undercompression and pores may dilate causing an increase in the internalstress against the surrounding concrete particles. Repeated freeze andthaw cycles result in the rupture and deterioration of the concretestructure due to fatigue stresses. See Beaudoin, J. J., and C. MacInnis“The mechanism of frost damage in hardened cement paste”, Cement andConcrete Research, (4)139-147, 1974. Cheng-yi H., and R. F. Feldman,“Dependence of frost resistance on the pore structure of mortarcontaining silica fume”. ACI Journal, September-October, pp. 740-743,1985. Collins, A. R. “The destruction of concrete by frost”, Journal ofthe Institute of Civil Engineers, London, Paper no. 5412, pp. 29-41,1944.

The permeability of concrete allows chloride ions, such as from de-icingagents, to penetrate through the osmotic process in which the ionsdiffuse from the high concentrate zone to the low concentration zone.Under wet conditions, the concentration of chloride ions within theconcrete becomes diluted, therefore, results in an increase in thedriving force of ions diffusion. Chloride ions are considered as a highoxidizing agent. In concrete pavements, these ions acceleration thecorrosion of steel reinforcing bars, thus reduce the life expectancy ofthe concrete structure itself In addition, chloride ions attack theconcrete matrix by breaking the cement paste bond. This leads to theformation of more cracks that weakens the structure. See Bentz, D. P.and Garboczi, E. J., “A Computer Model for the Diffusion and Binding ofChloride Ions in Portland Cement Paste,” NISTIR 5125, U.S. Department ofCommerce, February 1993.

Several methods have been developed to overcome the problem ofAlkali-Silica Reaction, such as the use of silica fume or fly ash(Sodium Carbonate) with the concrete mix. Silica fumes, as an additive,react chemically with calcium hydroxide in the presence of water withinthe concrete pores; this reduces the possibility of hydroxide to reactwith the aggregate silicates. On the other hand, sodium carbonatereduces the alkalinity of concrete through its reaction with thehydroxides. However, these methods are only applicable when silica fumesor fly ash are added to the concrete mix before paving.

As a treatment for existing concrete structures, solutions of sodiumsilicate have been used to partially neutralize the alkali materialswithin the concrete through a chemical reaction that produceshydrophilic silica gel material inside the pores (U.S. Pat. No.5,747,171). However, because such solutions have not had a very lowviscosity, their penetration efficiency has been very low. Therefore,treatment with silicate based solutions has typically been effectiveonly in the upper thin layer of the concrete pavement, which makes themless effective in addressing high hydrostatic pressures from below.

Application of water repellant materials to the surface of concretepavements such as those described in U.S. Pat. Nos. 5,338,345;5,958,601; and 6,037,429 can be effective in reducing water penetrationfrom the surface as they increase the surface tension of water to adegree that prevent it from passing through capillaries. However, suchmethods alone do not address moisture transmission from the negativeside of the substrate.

Other treatment methods have utilized tartaric acid and soda ash withPortland cement in a slurry phase that has been applied to the surfacein a thin coat. The presence of tartaric acid and soda ash producesinsoluble hygroscopic crystals that block moisture transmission becauseof the so-called crystal growth process as a result of the relativelyhigh affinity to moisture of these crystals. However, such method hasbeen inefficient because of the complexity in application (must blockoff and keep wet for four days) as well as its need for repeatedmaintenance (because it is an inherently surface adhering application asopposed to a penetrating material).

As a further disadvantage, available methods of treatment havehistorically attempted to solve the water and moisture problems inconcrete pavement by application of single techniques at a time.Therefore, complex problems have not been overcome without theimplementation of multiple treatments. There is a need for an affordablematerial that can address multiple significant water andmoisture-associated problems in concrete pavements in a singleapplication, especially for large areas of pavements such in the case ofconcrete highways, bridges and airport runways.

Applicant's Prior Products

A Chem-Crete CCC100™ product was introduced to the market in 1969 as awaterproofing material for concrete structures. It has gone throughseveral stages of research and development to improve its performanceand efficiency by adjusting its formulation as well as raw materialsinvolved and manufacturing conditions. The late Dr. Battista developedhis latest formula of CCC100 in 1990. It is commonly referred to as the“Original Formula”. CCC100 Original Formula, based on sodium silicate,is used globally as a waterproofing and hardening agent for old concretestructures as well as for its ability to work as a curing compound forfresh concrete. The waterproofing capability of CCC100 is achieved by aninternal reaction that is triggered by a catalyst contained within thematerial to produce insoluble hydrophilic crystals which fill the poresand capillary channels inside the concrete.

More particularly, CCC100 is a combination internal waterproofing agentand curing agent for new concrete or a waterproofing agent for curedconcrete. The product reacts with hydroxides (Portlandites) andtri-calcium silicate elements within the pore structure of a concreteassembly. The result of the reaction is the creation of acalcium-silicate hydrophilic grain with non-dilutent properties thatabsorb penetrating liquids and block the liquid passage through theconcrete assembly that is under the influence of hydrostatic pressures.CCC100 is a colorless, transparent liquid that penetrates concrete andmasonry building materials—protecting, preserving and strengthening themby:

Curing: CCC100 eliminates hairline cracking and temperature cracking onnew concrete. When applied to freshly finished concrete, CCC100 willuniformly cure the concrete through a chemical reaction as well as forma moisture barrier which eliminates temperature cracking.

Sealing: CCC100 penetrates into the concrete, forming a chemicalreaction which locks the pores from within, giving the concrete a deepseal.

Waterproofing: CCC100 becomes a permanent, integral part of theconcrete, thus waterproofing and substantially bonding and strengtheningthe structure of the concrete.

Hardening: CCC100 solidifies the component parts of the concrete intoone solid mass which increases the density, toughens and hardens. CCC100treated concrete has been tested 30% harder after 28 days than fullycured, untreated concrete. This hardening prevents dusting, pitting andrutting of concrete floors and other masonry surfaces.

Neutralizing Alkali: As the CCC100 progressively penetrates the concreteit neutralizes the alkali and forces it to the surface where it can bewashed off.

Bonding: CCC100 prepares the treated surface for paints, caulkingcompounds, adhesives and floor coverings and increases the bond and lifeof these materials. CCC100 contains no silicone and is coatable andcompatible with any type of covering.

Treatment Results: With one application of CCC100, concrete and othermasonry is cured, sealed and waterproofed and is rendered highlyresistant to oils, grease and most acids. The component parts of theconcrete are solidified into a solid mass which increases the density,toughens and hardens and prevents dusting, pitting and rutting of thesurface. The surface alkali is neutralized and efflorescence and theleaching of lime and alkali is stopped. The surface is prepared forpaint, adhesives and all floor coverings.

Treatable Materials: Concrete, concrete block, mortar, plaster, stucco,terrazzo, exposed aggregate and any sand, aggregate cement combination.

Limitations: Do not apply CCC100 in the following cases:

-   -   When temperatures fall below 35° F.    -   To areas previously treated with curing or sealing agents unless        these coatings have been removed by chemical or mechanical        means.

Note: Must be kept off glass, glazed tile and aluminum.

In 1992, and after intensive research under the directions of Dr.Battista, Chem-Crete developed another waterproofing product that isused strictly for old concrete, known as SofiX (CCC700). SofiX, based ontartaric acid and anhydrous sodium carbonate, has been proven to performefficiently in waterproofing and hardening old concrete structures withsevere moisture problems. Although a similar concept to the CCC100, whenapplied to concrete structures SofiX penetrates more deeply into thesurface to produce insoluble hygroscopic crystals, which have theability to block concrete pores and capillary channels. The hygroscopicproperty of those crystals allows them to travel further within theconcrete toward a moisture source in a continuous process.

More particularly, Chem-Crete SOFIX® is a crystallization waterproofingproduct in liquid form. It has the advantages of similar known priorpowder form crystallization waterproofing products, together with theadvantages of easy liquid application. The product can be applied toconcrete like a paint and results in the same waterproofing quality asthe prior known crystallization waterproofing cementitious coatings.Chem-Crete SOFIX is formulated with chemical agents that enhance deeppenetration within the concrete capillaries where the active chemicalsreact to form hygroscopic crystalline material which permanently blockconcrete pores. The chemical activity of these crystalline materials isreactivated upon further contact with moisture, and thus they keepgrowing inside the concrete providing dormant additional protection.

The chemicals in Chem-Crete SOFIX may include other active reagents thatreact with hydroxides (Portlandites) to produce di and tri calciumsilicate elements within the pore structure of a concrete assembly,resulting in more dense concrete and creating a hydrophiliccrystallization with non-dilutent properties. Under the influence ofhigh hydrostatic pressures, these crystals fill the voids, thus doublingthe pore-blocking effects towards the liquid passage through theconcrete assembly and vapor moistures.

Chem-Crete Sofix™ is a colorless, transparent liquid that penetratesconcrete and masonry building materials—protecting, preserving andstrengthening them.

USES: Warehouse floors, foundations and slabs, reservoirs, industrialplants, swimming pools, subway tunnels, elevator pits, interior walls inparking garages.

FEATURES:

-   -   Easy application    -   High waterproofing performance    -   Penetrates concrete and seals capillary tracts and hairline        cracks    -   Can be applied to old and green concrete    -   Protects concrete in-depth    -   Multiple function: waterproofing, sealing and bonding which        increase adhesive properties for products such as: epoxy        coatings, polyurethane coatings, asphalt coatings and paints.    -   Stops efflorescence    -   Cost effective    -   Non-toxic    -   Resists high hydrostatic pressure    -   Exterior and interior applications    -   Capillary waterproofing for concrete

TREATABLE MATERIALS: concrete, concrete block, mortar, plaster, stucco,terrazzo, exposed aggregate and any sand, aggregate cement combination.

LIMITATIONS: Do not apply Chem-Crete SOFIX in the following cases:

-   -   When temperatures fall below 35° F.    -   To areas previously treated with curing or sealing agents unless        these coatings have been removed by chemical or mechanical        means.

COVERAGE: Number of coats needed: One coat needed on new concrete after7 days of placing the concrete at the rate of 200 sq. ft. per gallon.For old concrete: one coat application at the rate of 150 sq. ft. pergallon. Coverage depends on the temperature and porosity of theconcrete.

STORAGE LIFE: One year—Agitate bucket or drum before using.

Both products, the CCC100 and the SofiX, are water-based, non-toxicmaterials. They have been proven to solve moisture problems in concreteunder moderate and severe conditions and to be used as a water barrierfor concrete surfaces prior to the application of any kind of adhesives.In addition, they have performed well to protect concrete structuresagainst freeze-thaw effect and chloride ions penetration from deicingsalts.

Both products are of a non-film forming type that protect concreteinternally. Although, they both work effectively, there was a need for aproduct which would protect concrete against water and moisture problemsat the surface, by repelling, while allowing the concrete to breath. Asa result, the CCC1000 product was developed in 1992 shortly prior tointroducing SofiX to the market. CCC1000 is a water-based concrete/stonesealer and water repellent. CCC1000, based on potassium methyl silicate,penetrates up to 2 inches depending on the porosity of concretestructures and reacts to permanently coat the inner surface of pores andcapillaries with a non-visible gel-like material that becomes part ofthe concrete substrate. It exhibits water sealing and repellingcapability.

More particularly, Chem-Crete 1000® is a ready to use, clear, somewhatpenetrating, liquid concrete sealer and water repellent. It iscolorless, non-staining, non-film forming and non-yellowing. Chem Crete1000 penetrates the surface and chemically reacts to become an integralpart of the substrate. The chemical action results in a gel-like coatingof the pore walls to block the ordinary capillary action of water. Thisproduces a highly effective, breathable, moisture barrier. Because theChem-Crete 1000 barrier is within the substrate, it is further protectedfrom weathering and helps keep treated surfaces clean by resisting theentrance of airborne dirt and impurities. It eliminates efflorescence,and spalling from freeze-thaw cycles and protects against airborne dirt,smog, industrial fumes, acid rain and most other atmospheric chemicals.The deterioration of surface paints and adhesives, due to alkali attackis eliminated. Surface textures and colors are not affected. Chem-Crete1000 is economical, fast and easy to use and is non-toxic, non-flammableand is a water clean-up product.

Chem-Crete 1000 is used above and below grade to protect againstmoisture penetration by capillary action. It is formulated to protectdense concrete and masonry surfaces in one application, without alteringthe color or textural appearance of the surface. Substrates includeprecast concrete, tilt-up concrete, monolithic concrete, stucco, clay,brick, limestone and other natural or manufactured stone. Chem-Crete1000 is formulated to protect porous masonry, concrete block and othersimilarly porous materials without altering the color or texturalappearance of the treated surface. It is a water based product and is anexcellent primer for paint.

Chem-Crete 1000 penetrating concrete sealer and water repellent is aformulation of clear solution derived from several chemical solids. Itis furnished in solution and requires agitation. The active ingredientsform a breathable moisture barrier within the treated substrate duringand following the drying-curing period. Chem-Crete 1000 is water basedand non-flammable.

All the Chem-Crete products above have been used together sequentially,usually starting with a single application of SofiX followed by anapplication of CCC100 and then a one-coat application of CCC1000. Areasthat were treated with this system were protected against a plurality ofproblems associated with water and water vapor, utilizing thehydrophilic and the hygroscopic properties of CCC100 and SofiX,respectively, as well as the repelling characteristic of CCC1000.However, in order to achieve this enhanced performance, the protectionsystem was complicated in the application technique, as many criticalsteps were involved. As a result, it constituted made a non-costeffective system for mass applications such as highways and airportrunways.

After intensive research, the instant inventor has now been able tocombine the essence and functionality of the above Chem-Crete productsinto new single products that are cost-effective, storable with anacceptable practical shelf life and that provide enhanced singletreatment protection for concrete substrates. Preferably, the newproduct is manufactured from scratch, using some of the same chemicalsused in the production of the three original Chem-Crete products, somedifferent chemicals and with improved ratios. In particular, the typeand quantity of performance enhancers and their ratios have beenadjusted. Less preferable versions could be produced by mixing certainamounts of prior CCC100, CCC1000 and/or SofiX concentrates significantlydiluted with water.

In accordance with the present invention, there is provided acomposition comprising a well-balanced aqueous mixture of activechemicals that are environmentally friendly and free of volatile organiccompound (VOC). Some of the chemicals act independently while some workin conjunction with each other and via chemical reactions to achieve thegoals of the treatment. The term “mixture” is used to indicate primarilya mixture of chemicals. This mixture is typically and preferablysubstantially in solution form However, some settling out is expected.The concentrations used can affect the solution form. An emulsion formis conceivable. A residue, or even a small amount of gel in the bottom,from the solution form is possible. Shaking or mixing prior to sprayingor rolling, etc. is advised. The term “multi-compounds” indicates aplurality of chemicals.

The chemical and physical functions of a preferred embodiment of thepresent invention can be summarized by noting the following beneficialfunction of certain components:

-   -   Surfactant (preferred embodiment being nonylphenol polyethylene        glycol ether): a component chemical that behaves as a wetting        agent in the mixture mixture to reduce the surface tension of        component chemicals, thus allowing certain components of the        product to deeply penetrate into concrete structures through        capillaries.    -   Antifoaming agent (preferred embodiment being isopropyl        alcohol): a component chemical that reduces or suppresses bubble        formation, thus eliminating air entrapment within the mixture        during the application.    -   Emulsifier & cleaner (preferred embodiment being a combination        of alkyl-benzene-sulfonic acid, sodium hydroxide and sodium        hypochlorite): an agent(s) that helps open concrete pores and        capillaries by emulsifying dirt and impurities to allow the        mixture to penetrate easily.    -   Water repellent (preferred embodiment being potassium methyl        siliconate): a component chemical that reacts and bonds to the        concrete surface resulting in a significant increase in the        surface tension of water, thus preventing water from penetrating        through capillaries.    -   Crystallization chemicals (preferred embodiment being a        combination of sodium hydroxide, sodium silicate, sodium        carbonate and/or tartaric acid): a group of active component        chemicals that generate a hygroscopic and/or hydrophilic        crystallization system, and preferably both, within the pores        and capillaries of concrete.

In preferred embodiments of the present invention, these activecomponent chemicals are combined together, through a preferredmulti-stage manufacturing process, to produce a new product thatpromises to more permanently solve moisture and water-associatedproblems in concrete pavements by a double or triple action techniquewith a single application. The water repelling efficiency shouldpreferably exceed that of the established federal specifications. Thecrystallization system adds to the water repellent feature thehygroscopic and/or hydrophilic behaviors, all together in one system.The product preferably can be stored and shipped in one container, witha shelf life of at least six months if handled properly, and can beadvantageously applied by spraying. Rolling or brushing is alsopossible, of course.

Furthermore, the present invention preferably does not have any effecton the color or appearance of the treated concrete.

SUMMARY OF THE INVENTION

The instant invention comprises an aqueous mixture for application toconcrete pavements for protection against water associated problems. Themixture comprises multi-compounds mixed into a relatively stable aqueousmixture form. In one embodiment, the compounds include alkali metalsilicate, potassium methyl siliconate and at least 50% by weight water.Preferably the compounds include at least one surfactant. Preferably thecompounds include at least one anti-foaming agent. Preferably thecompounds include at least one emulsifier/cleaner agent. Preferably thewater includes deionized water. Preferably the compounds also includetartaric acid and sodium carbonate.

The invention includes a method for protecting concrete pavementcomprising applying an aqueous chemical mixture to the concretepavement, preferably only once, and curing the mixture. The applying andcuring achieves from one mixture repelling water penetration at thepavement surface and blocking water penetration within concrete matricesof the pavement by at least hydrophilic or hygroscopic crystallization.Preferably the blocking includes blocking by hydrophilic and hygroscopiccrystallization.

The invention includes a method for making a stable containerizableaqueous mixture for application to concrete pavements to protect fromwater associated problems, the method comprising gradually adding alkalimetal silicate (preferably sodium silicate) to at least 50% by weightwater in a reactor and mixing; slowly introducing potassium methylsiliconate to the water/alkali metal silicate solution and mixing; andletting the material settle for approximately one hour while coveredbefore re-packing. Preferably the method also includes initially addingtartaric acid in small portions at a time to the water whilecontinuously agitating and adding sodium bicarbonate (preferablyanhydrous) in small portions at a time, mixing between adding additionalportions. Preferably also the method includes adding a water-basedmixture of at least one surfactant, at least one anti-foaming agent andat least one cleanser/emulsifier to the sodium silicate/water mixtureand mixing. The invention includes the product produced by the methodsof manufacture.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention can be obtained when thefollowing detailed description of the preferred embodiments areconsidered in conjunction with the following drawings, in which:

FIG. 1 illustrates untreated water problems in concrete structures andhow they can result in structural failure.

FIG. 2 illustrates common water associated problems in pavements.

FIG. 3 illustrates the behavior of hygroscopic and hydrophiliccrystalline material within concrete pores and capillaries under wet anddry conditions and its mechanism in eliminating water and vaportransmission.

FIG. 4 illustrates results of a freeze and thaw test for concrete sampletreated with the present invention compared to an untreated sample.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

The present invention is recommended for the treatment and protection oflarge scale concrete pavements, mainly concrete bridges, concretehighways and airport runways and concrete taxiways. Application of theinvention can be very simple, through a spraying mechanism that isadequate enough to spray large areas in a short period of time. Rollingor brushing or other application techniques are also possible. Therecommended coverage of the invention at an anticipated dilution rate is200 ft²/gallon in a single application. During the application ofpreferred embodiments there would be no need for a complete closure ofareas to be treated. In fact they could be opened to traffic shortlyafter the treatment, since the mixture preferably penetrates through thesurface in a relatively rapid process because of a preferred lowviscosity.

After the product is applied and as soon as its water starts to dry, thechemical action starts to take place at the surface as well as deeplywithin the concrete pores and capillaries.

As part of the preferred embodiment of the present invention, preferablypotassium methyl silicate reacts with carbon dioxide from the air withinthe upper layer of the pavement as well as at the surface. The chemicalreaction is activated using UV light to produce an invisible resin-likematerial that coats the surface as well as the walls of capillaries andpores. The material becomes part of the concrete structure via chemicalbonds that are highly resistant to strong acids and alkali solution aswell as most aggressive chemicals. The material functions as a waterrepellant by increasing the surface tension of water to a degree thatmakes it essentially impossible for water to penetrate treated pavementsthrough capillaries. As a result, the invisible resin-like materialcomponent maintains a dry surface that effectively resists damage causedby freeze and thaw. In addition, it results in significantly reducingthe moisture content of the concrete, thereby bringing down the drivingforce for chloride ions penetration to a negligible limit. The waterrepelling function of the resin-like surface coating material componentof the present invention should remain essentially permanent for thelife span of the pavement, which tends to eliminate need for additionaltreatments.

As a further part of the preferred embodiment, multiple simultaneouschemical reactions take place within the capillaries and pores of theconcrete matrix as a result of the application of an embodiment of thepresent invention. Those reactions are triggered and/or accelerated bythe increase in the concentration of chemicals as a result of waterevaporation. Two major reactions are: one, tartaric acid reacts withsodium carbonate, triggered by the in increase in concentration as aresult of water evaporation, to produce hydrated crystals of sodiumtartrate. Two, sodium silicate (or an alkali metal silicate) reacts withcalcium hydroxide from the concrete matrix to produce tri-calciumsilicate. Further, both reactions when present interact chemically andkinetically with each other. As a result, preferably sodium tartrate andtri-calcium silicate become physically bonded to each other in a complexform of insoluble crystallization material These crystals combine boththe hygroscopic and hydrophilic properties with a great affinity towater in its liquid and vapor phase.

The preferred hygroscopic and hydrophilic crystalline material,generated by the preferred embodiment of the invention, provides almostefficient protection for concrete pavements by optimally controlling themass transfer of water and water vapor across the concrete matrixthrough capillaries and pores. The hydrophilic property of the crystalsworks mostly against water in the liquid stage while the hygroscopiccharacteristic works against water vapor.

Because of the hydrophilic behavior, under wet conditions, the crystalsabsorb water and swell in the form of a compressible gel material tofill the voids. As a result, they prevent further water from passingthrough Experimental work shows that these crystals have the ability toabsorb enough water to make them swell up to sixteen times their size inthe dry stage. The swelling stops as soon as the crystals reach the sizeof the void they are contained in.

On the other hand, the hygroscopic behavior becomes highly effective inthe presence of water vapor, especially under relatively highhydrostatic pressures. Because of their extremely high affinity tomoisture, the crystals continuously crawl slowly inside the pores andcapillaries toward the source of moisture. As they absorb moisture, thesodium tartrate part of the crystals becomes more hydrated. This resultsin what is called crystal growth. The crystal growth leads toeliminating moisture transmission across the concrete matrix. Our testsshow that the crystals were able to grow and travel about 3.5″ over aperiod of 12 weeks.

Under dry conditions, the crystals release the moisture they absorbedthrough evaporation. This results in bringing back these crystals totheir original size, allowing the concrete to breath The crystals staydormant till the swelling and crystal growth processes are reactivatedas a result of any increase in the moisture content inside the concretefrom any side.

FIGS. 1 and 2 illustrate water problems in concrete structure. FIG. 3illustrates the behavior of the preferred hygroscopic and hydrophiliccrystalline material within concrete pores and capillaries under wet anddry conditions and its mechanism in eliminating water and vaportransmission.

The preferred embodiments of the present invention, as a result, cancomprehensively protect concrete pavements against water and moistureassociated problems. A crystallization system minimizes the dissolutionof calcium hydroxide contained within the concrete by moisture contact.As result, alkali silica reactions are minimized. Furthermore,minimizing water penetration and moisture transmission can dramaticallyreduce the driving force for chloride ion diffusion into concrete. As aresult, the structure becomes protected against chloride ion attack. Inaddition, the structure will be protected against damage caused byrepeated freezing and thawing cycles. As illustrated in FIG. 4, freezeand thaw test shows that after 150 cycles of freeze and thaw, the damageto a treated concrete sample was less than the damage caused by 25cycles to an untreated sample.

COMPOSITION OF PREFERRED EMBODIMENTS OF THE INVENTION

One preferred embodiment of the invention is formulated by combiningnine different chemicals in a mixture form using deionized water.

To our knowledge, an optimum quantitative chemical composition of theinvention can be achieved if a mixture is prepared using the data givenin Table 1 on weight basis. Such composition should provide a mixture ofabout 27% solid content that has a very low viscosity, of approximately2.4 centipoises, to assure deep penetration. TABLE 1 Optimum chemicalcomposition of the invention. Chemical Name wt. % AlkylbenzensulfonicAcid (pure) 0.008 Isopropyl Alcohol (Anhydrous) 0.121 NonylphenolPolyethylene Glycol Ether (pure) 0.013 Sodium Hydroxide (50% NaOHaqueous solution) 0.005 Sodium Hypochlorite (12.5% NaOCl aqueoussolution) 0.009 Sodium Silicate solution, (40% solid content) 19.212Tartaric Acid (pure solid form measured by weight) 1.816 AnhydrousSodium Carbonate (pure solid measured by weight) 1.288 Potassium MethylSiliconate (40% aqueous solution) 4.312 Deionized water 73.217 Total 100

Altering the chemical composition of the above preferred embodiment ofthe present invention by adjusting the weight percentage of one or morechemical ingredients, to a certain degree, should not have a significanteffect on the composition's overall performance, especially as long asthe method of application is adjusted accordingly. For instance, areduction in the solid content results in a diluted form of theinvention. In such embodiment the material should be applied to concretepavements at a higher rate. The overall performance of the mostpreferred embodiment of the invention in treated concrete pavements isbelieved to be acceptable if the content of the above chemicals remainapproximately within the ranges given in Table 2. TABLE 2 Minimum andmaximum weight percentage of chemicals through which the invention willremain effective. Minimum Maximum Chemical Name wt. % wt. %Alkylbenzensulfonic Acid (pure) 0.004 0.020 Isopropyl Alcohol(Anhydrous) 0.050 0.300 Nonylphenol Polyethylene Glycol Ether (pure)0.005 0.075 Sodium Hydroxide (50% NaOH aqueous solution) 0.002 0.025Sodium Hypochlorite (12.5% NaOCl aqueous 0.003 0.025 solution) SodiumSilicate solution, (40% solid content) 7.500 25.000 Tartaric Acid (puresolid form measured by 0.750 3.500 weight) Anhydrous Sodium Carbonate(pure solid 0.532 2.482 measured by weight) Potassium Methyl Siliconate(40% aqueous 1.650 7.500 solution) Deionized water 65.000 82.500

METHODS OF PRODUCTION

Production of the present invention preferably utilizes a multi-stepprocedure for mixing the chemicals, believed to minimize anyinteractions that may cause the material to crystallize duringmanufacturing. For this purpose a reactor vessel with a medium speedagitator is recommended.

Although the invention may be produced in one or two steps, takingcertain precautions, to our best knowledge the chemicals of the mostpreferred embodiment are best mixed in three different stages. Theproduct of the first stage is referred to as the mix1. The product ofthe second stage is referred to as the mix2. Both mix1 and the mix2 areconsidered as intermediate products for the purpose making the mostpreferred finished product in the preferred three stages.

Disclosed below, is the best procedure as well as, to our knowledge, thebest chemical composition, to be used for the making of the mostpreferred embodiment of the invention in a preferred ready-to-use form.

Stage One: Making of Mix1

Batch size=100 Liters, Net weight=98.896 kg TABLE 3 Materials requiredfor the manufacturing of a 100 liters of Mix1 (Performance Enhancers)Chemical Weight (kg) Deionized water 93.830 Sodium Hydroxide (50% NaOHaqueous solution) 0.153 Nonylphenol Polyethylene Glycol Ether (pure)0.423 Sodium Hypochlorite (12.5% NaOCl aqueous solution) 0.298Alkylbenzensulfonic Acid (pure) 0.265 Isopropyl Alcohol (Anhydrous)3.927 Total Weight 98.896Mixing Procedure:

-   -   1. Place the deionized water in the reactor and start the mixer        at a medium speed.    -   2. Add the sodium hydroxide solution and mix for about 2        minutes.    -   3. Add the Nonylphenol Polyethylene Glycol Ether (C₃₃H₆₀O₁₀) and        agitate for 5 minutes.    -   4. Gradually add the sodium hypochlorite solution and agitate        for 5 minutes.    -   5. Add alkylbenzensulfonic acid and agitate for 15 minutes.    -   6. Reduce the mixer speed and gradually pour the isopropyl        alcohol and mix for additional 10 minutes.    -   7. Cover the container and allow the material to cool to room        temperature and settle for 24 hours before using in production        of the concentrate.        Stage Two: Making of Mix2

Batch size=100 Liters, Net weight=117.915 kg TABLE 4 Materials requiredfor the manufacturing of a 100 liters of Mix2 Chemical Weight (kg)Deionized water 42.125 Sodium Silicate solution, 65.406 (40% solidcontent) Mix1 from Stage One 10.384 Total Weight 117.915Mixing Procedure:

-   -   1. Place the deionized water in the reactor and start the mixer        at a medium speed.    -   2. Gradually add the sodium silicate solution and mix for about        15 minutes.    -   3. Gradually add the Mix1 and continue mixing for an additional        10 minutes.        Stage Three: Making of the Finished Product

Batch size=100 Liters, Net weight=109.552 kg TABLE 5 Materials requiredfor the manufacturing of a 100 liters of the Invention in itsready-to-use form. Chemical Weight (kg) Deionized water 63.487 TartaricAcid (pure solid form measured by weight) 1.989 Anhydrous SodiumCarbonate (pure solid measured by 1.411 weight) Mix2 from Stage Two37.945 Potassium Methyl Siliconate (40% aqueous solution) 4.72 Total109.552Mixing Procedure:

-   -   1. Place the deionized water in the reactor and start the mixer        at a medium speed.    -   2. Add small portions of the tartaric acid at a time while        continuously agitating. Make sure that all the acid crystals        have dissolved before adding a second portion. Continue mixing        for about 15 minutes after adding the whole amount of the acid.    -   3. Using very small portions at a time, add the sodium carbonate        slowly to prevent coagulation. Allow 2-3 minutes of mixing        before adding additional portions. Continue mixing for another        15 minutes at low speed.    -   4. Gradually add Mix2, mixing for about 10 minutes thereafter.    -   5. Slowly introduce the potassium methyl siliconate mixture, mix        for 5 minutes, and then let the material settle for one hour        while covered before repacking.

The foregoing description of preferred embodiments of the invention ispresented for purposes of illustration and description, and is notintended to be exhaustive or to limit the invention to the precise formor embodiment disclosed. The description was selected to best explainthe principles of the invention and their practical application toenable others skilled in the art to best utilize the invention invarious embodiments. Various modifications as are best suited to theparticular use are contemplated. It is intended that the scope of theinvention is not to be limited by the specification, but to be definedby the claims set forth below.

1. An aqueous mixture for application to concrete pavements forprotection against water associated problems, comprising:multi-compounds mixed into a stable aqueous mixture form, the compoundsincluding alkali metal silicate, potassium methyl siliconate, asurfactant, an emulsifier and at least 50% by weight water; and whereinthe mixture is sealed into a container such that an unopened containermaintained above 10° C. has a shelf life of at least six months.
 2. Themixture of claim 1 wherein the compounds include tartaric acid andsodium carbonate.
 3. The mixture of claim 2 wherein the compoundsinclude at least one anti-foaming agent.
 4. The mixture of claim 3wherein the compounds include at least one cleaner agent.
 5. The mixtureof claim 4 wherein the water includes deionized water, the anit-foamingagent includes isopropyl alcohol and the cleaner includes sodiumhydrochlorite.
 6. The mixture of claims 1, 2, 3, 4 or 5 wherein thesurfactant includes nonylphenol polyethylene glycol ether; and theemulsifier includes a fatty acid and at least one of sodium hydroxide,tetra potassium pyrophosphate and hexameta potassium phosphate.
 7. Themixture of claim 6 wherein the fatty acid includes alkylbenzensulfonicacid.
 8. The mixture of claims 1, 2, 3, or 4 wherein the water includesdeionized water.
 9. The mixture of claim 6 wherein the water includesdeionized water.
 10. An aqueous mixture for application to concretepavements for protection against water associated problems, comprising:deionized water; between 7.500% to 25.000% parts by weight sodiumsilicate solution (40% solids content); between 1.650% to 7.500% byweight potassium methyl siliconate (40% aqueous solution); between0.004% to 0.020% by weight (pure) alkylbenzensulfonic acid; between0.050% and 0.300% by weight (anhydrous) isopropyl alcohol; between0.005% to 0.075% (pure) nonylphenol polyethylene glycol ether; between0.002% to 0.025% by weight sodium hydroxide (50% NaOH aqueous solution);between 0.003% to 0.025% by weight sodium hypochlorite (of a 12.5% NaOClaqueous solution); between 0.750% to 3.500% by weight tartaric acid(pure solid form measured by weight); and between 0.532% to 2.482% byweight anhydrous sodium carbonate (pure solid measured by weight); mixedinto a stable aqueous mixture form.
 11. The aqueous mixture of claim 10,comprising; approximately 0.008% by weight alkylbenzensulfonic acid(pure); approximately 0.121% by weight isopropyl alcohol (anhydrous);approximately 0.013% nonylphenol polyethylene glycol ether (pure);approximately 0.005% by weight sodium hydroxide (50% NaOH aqueoussolution); approximately 0.009% sodium hypochlorite (12.5% NaOCl aqueoussolution); approximately 19.212% by weight sodium silicate solution (40%solid content); approximately 1.816% by weight tartaric acid (pure solidform measured by weight); approximately 1.288% anhydrous sodiumcarbonate (pure solid measured by weight); approximately 4.312% byweight potassium methyl siliconate (40% aqueous solution); andapproximately 73.217% by weight deionized water.
 12. A method forprotecting concrete pavement, comprising; applying an aqueous chemicalmixture to the concrete pavement; and curing the mixture; thereby, bythe means of the application of one mixture, repelling water penetrationat the pavement surface; and blocking water penetration within concretematrices of the pavement by at least hydrophilic crystallization.
 13. Amethod for protecting concrete pavement, comprising; applying an aqueouschemical mixture to the concrete pavement; and curing the mixture;thereby, by the means of the application of one mixture, repelling waterpenetration at the pavement surface; and blocking water penetrationwithin concrete matrices of the pavement by at least hygroscopiccrystallization.
 14. The method of claim 12 wherein the blocking ofwater penetration within concrete matrices of the pavement includesblocking by hygroscopic crystallization.
 15. A method for making astable containerizable aqueous mixture for application to concretepavements to protect from water associated problems, comprising: (1)forming a dilute mixture of at least a surfactant and emulsifier; (2)gradually adding sodium silicate to water in a reactor and mixing; (3)gradually adding the surfactant/emulsifier mix to the sodium silicatemix; (4) adding to water tartaric acid in small portions at a time whilecontinuously agitating; (5) adding sodium bicarbonate in small portionsat a time to the tartaric acid mix; (6) gradually adding thesurfactant/emulsifier/sodium silicate mix to the tartaric acid/sodiumbicarbonate mix; (7) slowly introducing potassium methyl siliconate tothe surfactant/emulsifier/sodium silicate/tartaric acid/sodiumbicarbonate mix and mixing; and (8) letting the material settle forapproximately one hour while covered before containerizing; whereby acontainer maintained above 10 degrees C. has a shelf life of at leastsix months.
 16. The method of claim 15 including in step (1) forming awater based mixture of (a) at least one of sodium hydroxide, tetrapotassium pyrophosphate and hexameta potassium phosphate; (b) a fattyacid; and (c) nonylphenol polyethylene glycol ether.
 17. The method ofclaim 16 including in step (1) adding sodium hypochlorite and isopropylalcohol to the mixture.
 18. The method of claim 16 wherein the fattyacid includes alkylbenzensulfonic acid.
 19. The method of claims 15, 16,17 or 18 wherein the water comprises deionized water.
 20. The productproduced by the method of claims 15, 16, 17 or
 18. 21. The productproduced by the method of claim
 19. 22. The method of claim 12 thatincludes opening treated pavement for normal use within at least onehour of application.
 23. An aqueous mixture for application to concretepavements for protection against water associated problems, comprising:multi-compounds mixed into a stable aqueous mixture form, the compoundsincluding water; at least 7.5% by weight sodium silicate solution (40%solids content); at least 0.75% by weight tartaric acid (pure solid formmeasured by weight); at least 0.5 % by weight anhydrous sodium carbonate(pure solid measure by weight); an emulsifier including at least one ofsodium hydroxide, tetra potassium pyrophosphate and hexameta potassiumphosphate together with a fatty acid; and a surfactant includingnonylphenol polyethylene glycol ether; and wherein the mixture is sealedinto a container such that an unopened container maintained above 10° C.has a shelf life of at least six months.
 24. The mixture of claims 1, 2,3, 4, or 5 wherein the alkali metal includes sodium.
 25. The mixture ofclaims 1, 2, 3, 4, or 5 wherein the sodium carbonate includes anhydroussodium carbonate.